As the liquid crystal display technology develops, a curved surface screen has been invented. For consideration of a curved surface design, a BPS (Black Photo Spacer) design is usually adopted to omit the manufacturing process of a BM (Black Matrix), because a BPS not only has a supporting function like a PS (Photo Spacer), but also can shield a frame area from light, i.e. a BM and a PS are manufactured in one process. Besides, the BPS is designed on an array substrate, and to be specific, the BPS is provided on a lower substrate, which can avoid undesirable optical characteristics caused by misalignment of an upper substrate and a lower substrate. However, a BPS design is not compatible with the UV2A (Ultraviolet Vertical Alignment) technology, the reason of which is briefly explained below.
The UV2A technology is a method for liquid crystal vertical alignment, the principle of which is as below. Ultraviolet passes through a mask and irradiates different regions of a pixel, causing a photochemical reaction on a PI (Polyimide) film. Then after liquid crystals are dispensed, alignment of liquid crystals at a certain angle is achieved. Compared with PSVA (Polymer Stabilized Vertical Alignment), UV2A has advantages like a higher liquid crystal efficiency, a lower cost, etc.
As shown in FIG. 1A and FIG. 1B, during the UV2A process, a mask 1 is needed. Considering that different regions of a pixel need to be exposed, during the process of exposure and translation, the mask 1 should be aligned with and be used to track a specified pattern in a panel 2, so as to ensure precision. For an ordinary substrate, a BM 3 or RGB (Red, Green, and Blue) color resists are provided on a side of a CF (color filter) substrate, and the mask 1 might be required to be aligned with and be used to track the BM 3 or the RGB patterns.
As shown in FIG. 2A and FIG. 2B, when the BPS technology is used, only an ITO (Indium Tin Oxide) transparent electrode layer is provided on a side of a CF substrate, no PS or BM being provided. Thus, no pattern can be tracked and exposed as the UV2A technology requires. Therefore, the BPS technology is not compatible with the UV2A technology, due to which it is unlikely to benefit from advantages of the two technologies simultaneously.
In view of the above, the present disclosure provides a method for improving transmittance of flat or curved liquid crystal display panel. The method is able to make the BPS technology be compatible with the UV2A technology, thanks to which a better liquid crystal display transmittance can be obtained.